The present invention relates to an apparatus for the shaping of plastics material or glass pre-forms into plastics material containers. Machines of this type are known from the prior art. Usually machines of this type have a rotatable carrier on which are arranged a plurality of blow moulding stations. In this case these blow moulding stations or shaping stations have moulded parts in each case which can be closed in order to form a cavity in this way inside which the plastics material or glass pre-forms are expanded to form the plastics material containers, in particular by being acted upon with compressed air. In this case it is usual for guide cams which close the two mould parts with each other to be provided. In addition, locking mechanisms (in part with separate guide cams) which lock the blow mould in a closed state are known from the prior art, which is helpful since very high pressures occur in the interior of the blow mould. As a result of the use of a locking means, the cam which is responsible for the opening and closing can be kept short (in the region where the mould carrier for the removal of the bottle and for the insertion of a pre-form is situated), since the locking automatically keeps the halves of the mould carrier closed for the remainder of the revolution of the blow moulding wheel. The blow moulding machines in which the locking means is actuated by a separate mechanism usually have two locking cam segments which are separate from each other. One (locking cam segment) is situated in the region just in front of the cam for opening the blow mould parts, as viewed in the running direction of the blow moulding wheel. One is situated in the region just after the cam for closing the blow mould parts. No cam which co-operates with the locking means is provided between them. The cam follower (usually a steel roller) mounted on the locking means must therefore be accelerated twice by a cam per revolution of the blow moulding wheel. In addition, the cam followers are subjected to directions of rotation which change in part or respectively it is necessary for two cam rollers to be provided per locking means in order to avoid a change in the direction of rotation. The cam segments of the locking means are designed to be capable of being deflected in part for reasons of safety, if locking cannot be carried out on account of jamming, the cam has to swing out on account of excessive loading in order to prevent damage to the locking means.
These procedures have proved as being effective, but are in part relatively complicated technically or are disadvantageous in terms of wear.